A number of connectors are available to terminate a coaxial cable so as to connect the cable to various electronic devices, such as switches, distribution boxes, manifolds, and electronic devices. In a typical coaxial cable network, a “drop” cable is used to carry the signal, which may include analog or digital TV signals, internet signals, security monitoring signals, etc., from the rigid coaxial cable near the road to the end user's home. The connector in many cases has to be installed outside of the end user's home so that the servicing and installation personnel can perform troubleshooting as well as connecting and disconnecting the signal without entering the end user's premises. The connector is thereby exposed to weather elements, including periods of high moisture, temperature fluctuations, rain, snow, etc. In addition, as the connectors are installed outdoors, they are prone to unauthorized assess, tampering, or theft.
The drop cable typically has an elongated copper or a copper clad steel center conductor, surrounded by a dielectric in turn surrounded by a conducting braid and/or foil which is used as a shield, which is in turn surrounded by a polymer-based insulating jacket, typically made of PVC or PE.
A typical interconnection of the “F” female port and “F” male connector is shown in FIG. 1. The “F” female port and “F” male connector are interconnected and sealed with a sleeve which is independent of the connector but is dependent on the attachment of the “F” male connector to the “F” female port. The sleeve provides the critical protection against moisture. Inadequate sealing of the connection is known to cause a non-hermetic seal and thereby allow penetration of moisture into the interconnection. The signal quality is then compromised at the subscriber's location due to parasite electrical pathways between the center conductor and the shielding formed by moisture, as well as the oxidation and corrosion of the internal connector components and of the center conductor, with consequent deterioration of the quality of the connection.
Security shields protecting the interconnection and providing security against unauthorized access, theft, and tampering are known in the art. A typical security shield is a shell slideably fitting over the interconnection and preventing physical access. A special tool is commonly required to attach the security shield. Once the security shield is attached, it is impossible to disconnect the connectors without first removing the security shield. However, typical security shields are difficult to fit over the sealing sleeves such as shown in FIG. 1 due to spatial constraints.
U.S. Pat. No. 4,824,386 discloses a security connector with a shield 22b and a retaining ring 152 in FIGS. 4 and 5. There is no provision for a weather seal. The retaining ring 152 cannot provide any weather seal or perform sealing gasket-like functions being cut in the middle.
U.S. Pat. No. 4,822,293 discloses a sealing housing 10 which includes a tubular member 12 and two O-rings 40 and 46. Although not a security sleeve, housing 10 is very similar to one. This design requires a complicated assembly and insertion of gaskets 40 and 46 which can fall off during the connector assembly without the assembler noticing.
U.S. Pat. No. 4,674,818 discloses a hollow elastically deformable sealant member 180 which provides a weather seal between the male and female “F” connectors. This sealing apparatus is similar to the prior art embodiment shown in FIG. 1, and is subject to leakage through the treads of the male threaded member, especially when exposed to temperature fluctuations when in service. Another disadvantage of this sealing apparatus is the extra part of the assembly represented by the elastically deformable sealant member and the extra time required when performing assembly in the field.
U.S. Pat. No. 4,545,633 discloses an O-ring 124 (FIG. 2) which seals between outer shell 98 and tubular component 68 of housing 66. Outer shell 98 performs a locking function similar to a security shield.
U.S. Pat. No. 5,439,386 discloses a locking member 100 (FIGS. 7, 7A, 7B) with O-rings 38 and 154 providing a seal between the locking member, chassis mounting portion 6, and adaptor 8. This is a complicated design requiring complex assembly and multiple sealing gaskets.
None of the prior art has addressed the tight weather seal requirements for the “F” interconnection as well as the security shielding requirements, along with the concomitant need to prevent direct detaching or loosening of the connector from the mating port, unauthorized access, tampering, and theft, in an economic, easy to assemble, and compact package. The complexity of design and number of required parts makes some of these connectors impractical and expensive to manufacture. In addition, the procedures required to assemble these connectors in the field, often in inclement weather conditions, are complicated.